A friend who burns easily is travelling to Africa during the dry season. What is the strongest sunblock on the market, and is it actually sensible to use - that is, would it potentially prevent sweating which may not be healthy for the body?

5 Answers
5

The strongest sunblock would be to wear a big hat and long sleeves and pants (preferably white clothing). I mean this with all sincerity. The only way to truly block the sun in the most effective way is to take steps to prevent it from reaching your skin.

A technicality but arguably the best answer so I'll accept this one.
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Mark MayoJul 15 '11 at 10:52

I'm the friend who burns easily (30 min on a sunny British winter day / sub 5 min NZ summer) I can say your answer and some spf 50 did the trick. The one time I was exposed with out sun block I didn't burn as quickly or as hard as I expected. Obviously this wont be the case for everyone or an excuse not to take the risk seriously. Something else I was advised by my GP is some anti-malarial's can make skin more susceptible to burning, I can't remember which one does but Malarone doesn't.
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StuartOct 17 '11 at 13:39

doxycycline, I believe, is the one that makes you more susceptible to the sun.
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Mark MayoOct 19 '11 at 11:19

Great answer, I wanted to write exactly the same
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TomasFeb 17 '12 at 16:29

In addition to sunblock, long sleeves, a hat and sunglasses, you should also consider Zinc creams (Zinc Oxide). It's a physical barrier, resists sweating and for these reasons is what cricketers wear when they have to play in the sun all day. It's also hypoallergenic and is used to prevent some skin conditions (again by providing a physical barrier between the skin and the environment).

The usual explanation for 30+ being worthless is "who burns in half an hour? With 30 you could be outside for 15 hours and not get burned, so you don't need higher." Well, I can burn in 15 min in some cases, if I'm canoe camping I might be in the sun for 16 hours, and I don't want to burn or even tan, so measuring by "time till you have a sunburn" is not good. I buy 45 or 50, but supplement with a hat and long sleeves.
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Kate GregoryJun 29 '11 at 16:14

I believe the key is to reapply and reapply rather than to expect one application of a high SPF to last. I don't burn that easily but it depends on the conditions. I once burned in seven minutes.
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hippietrailJun 29 '11 at 17:18

I think even if you keep applying SPF 15 after (15 * however long you would burn in) you will have a burn. I have had some wicked burns being on the water with SPF 15.
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Kate GregoryJun 29 '11 at 18:01

In Australia the advice advertized by the government is to only use SPF 30+ and reapply every two hours I believe.
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hippietrailJun 29 '11 at 20:35